Abstract
The healing of neuronal injuries is still an unachieved goal. Medicine-based therapies can only extend the survival of patients, but not finally lead to a healing process. Currently, a variety of stem cell-based tissue engineering developments are the subject of many research projects to bridge this gap. As yet, neuronal differentiation of induced pluripotent stem cells (iPS), embryonic cell lines, or neuronal stem cells could be accomplished and produce functional neuronally differentiated cells. However, clinical application of cells from these sources is hampered by ethical considerations. To overcome these hurdles numerous studies investigated the potential of adult mesenchymal stem cells (MSCs) as a potential stem cell source. Adult MSCs have been approved as cellular therapeutical products due to their regenerative potential and immunomodulatory properties. Only a few of these studies could demonstrate the capacity to differentiate MSCs into active firing neuron like cells. With this study we investigated the potential of Wharton's Jelly (WJ) derived stem cells and focused on the intrinsic pluripotent stem cell pool and their potential to differentiate into active neurons. With a comprehensive neuronal differentiation protocol comprised of mechanical and biochemical inductive cues, we investigated the capacity of spontaneously forming stem cell spheroids (SCS) from cultured WJ stromal cells in regard to their neuronal differentiation potential and compared them to undifferentiated spheroids or adherent MSCs. Spontaneously formed SCSs show pluripotent and neuroectodermal lineage markers, meeting the pre-condition for neuronal differentiation and contain a higher amount of cells which can be differentiated into cells whose functional phenotypes in calcium and voltage responsive electrical activity are similar to neurons. In conclusion we show that up-concentration of stem cells from WJ with pluripotent characteristics is a tool to generate neuronal cell replacement.